<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<title>输入Email相关字符自动提示Email地址</title>
<script src="../../vendor/jquery-1.11.0.min.js"  type="text/javascript"></script>
<style type="text/css">
body
{
	margin:0px;
	padding:0px;
	font-family:Arial;
	font-size:12px;
	padding:10px;
}
#myemail, .newemail, .newemailtitle{    
	cursor:default;
	line-height:18px;
}
</style>
</head>
<body>
Email <input id="me" type="text" value="" style="width:150px; height:18px; line-height:18px; border:1px solid #999;">
<script type="text/javascript">
var nowid;
var totalid;
var can1press = false;
var emailafter;
var emailbefor;
$(document).ready(function(){	
    $("#me").focus(function(){ //文本框获得焦点，插入Email提示层
        $("#myemail").remove();
	$(this).after("<div id='myemail' style='width:170px; height:auto; background:#fff; color:#6B6B6B; position:absolute; left:"+$(this).get(0).offsetLeft+"px; top:"+($(this).get(0).offsetTop+$(this).height()+2)+"px; border:1px solid #ccc;z-index:5px; '></div>");
        if($("#myemail").html()){
             $("#myemail").css("display","block");
	$(".newemail").css("width",$("#myemail").width());
		can1press = true;
        } else {
             $("#myemail").css("display","none");
		can1press = false;
        }		
    }).keyup(function(){ //文本框输入文字时，显示Email提示层和常用Email
		var press = $("#me").val();
		if (press!="" || press!=null){
		var emailtxt = "";			
		var emailvar = new Array("@163.com","@126.com","@yahoo.com","@qq.com","@sina.com","@gmail.com","@hotmail.com","@foxmail.com");
		totalid = emailvar.length;
			var emailmy = "<div class='newemail' style='width:170px; color:#6B6B6B; overflow:hidden;'><font color='#D33022'>" + press + "</font></div>";
			if(!(isEmail(press))){
			    for(var i=0; i<emailvar.length; i++) {
				    emailtxt = emailtxt + "<div class='newemail' style='width:170px; color:#6B6B6B; overflow:hidden;'><font color='#D33022'>" + press + "</font>" + emailvar[i] + "</div>"
			    }
			} else {
			    emailbefor = press.split("@")[0];
			    emailafter = "@" + press.split("@")[1];
			    for(var i=0; i<emailvar.length; i++) {
			         var theemail = emailvar[i];
			         if(theemail.indexOf(emailafter) == 0)
			         {
				         emailtxt = emailtxt + "<div class='newemail' style='width:170px; color:#6B6B6B; overflow:hidden;'><font color='#D33022'>" + emailbefor + "</font>" + emailvar[i] + "</div>"
				     }
			    }
			}
			$("#myemail").html(emailmy+emailtxt);
			if($("#myemail").html()){
				 $("#myemail").css("display","block");
				 $(".newemail").css("width",$("#myemail").width());
				 can1press = true;
			} else {
				 $("#myemail").css("display","none");
				 can1press = false;
			}
			beforepress = press;
		}
		if (press=="" || press==null){
		    $("#myemail").html("");		
		     $("#myemail").css("display","none");    
		}				
    })
	$(document).click(function(){ //文本框失焦时删除层
        if(can1press){
			$("#myemail").remove();
			can1press = false;	
			if($("#me").focus()){
			    can1press = false;
			}
		}
    })
    $(".newemail").live("mouseover",function(){ //鼠标经过提示Email时，高亮该条Email
        $(".newemail").css("background","#FFF");
        $(this).css("background","#CACACA");		
		$(this).focus();
		nowid = $(this).index();
    }).live("click",function(){ //鼠标点击Email时，文本框内容替换成该条Email，并删除提示层
        var newhtml = $(this).html();
        newhtml = newhtml.replace(/<.*?>/g,"");
        $("#me").val(newhtml); 
        $("#myemail").remove();
    })
	$(document).bind("keydown",function(e)  
	{     
		if(can1press){
			switch(e.which)     
			{            
				case 38:
				if (nowid > 0){		
					$(".newemail").css("background","#FFF");
					$(".newemail").eq(nowid).prev().css("background","#CACACA").focus();
					nowid = nowid-1;		
				}
				if(!nowid){
					nowid = 0;
					$(".newemail").css("background","#FFF");
					$(".newemail").eq(nowid).css("background","#CACACA");		
					$(".newemail").eq(nowid).focus();				
				}
				break;       
		
				case 40:
				if (nowid < totalid){				
					$(".newemail").css("background","#FFF");
					$(".newemail").eq(nowid).next().css("background","#CACACA").focus();	
					nowid = nowid+1;			
				}
				if(!nowid){
					nowid = 0;
					$(".newemail").css("background","#FFF");
					$(".newemail").eq(nowid).css("background","#CACACA");		
					$(".newemail").eq(nowid).focus();				
				}
				break;  
		
				case 13:
				var newhtml = $(".newemail").eq(nowid).html();
				newhtml = newhtml.replace(/<.*?>/g,"");
				$("#me").val(newhtml); 
				$("#myemail").remove();
			}
		}   
	})
}) 
//检查email邮箱
function isEmail(str){
    if(str.indexOf("@") > 0)     
    {     
        return true;
    } else {
        return false;
    }
}
</script>
在输入框中输入“qq”、“Sina”、“163”等等可以看到效果
</body>
</html>